Bonilla Melvin M, Zeh Jeanne A, Zeh David W
Department of Biology and Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, NV, USA.
Department of Environmental Health, T.H. Chan School of Public Health, Harvard University, Boston, MA, USA.
Bioessays. 2016 Apr;38(4):355-66. doi: 10.1002/bies.201500176. Epub 2016 Mar 1.
Female choice for traits signaling male genetic quality is expected to erode heritable variation in fitness, undermining the benefits of choice. Known as the lek paradox, this contradiction has motivated extensive population genetic theory, yet remains unresolved. Recent modeling by Bonduriansky and Day concludes that costly female preference is best maintained when male condition is determined by environmentally induced factors transmitted across single generations. Here, we reformulate their model in explicitly epigenetic terms, and review evidence that environmentally induced paternal effects are mediated through epigenetic changes in sperm. Noncoding RNA expression, DNA methylation and histone modifications are highly sensitive to diet, stress, toxicants and stochastic events. Epigenetic variation renews each generation and cannot be exhausted by selection. By choosing well-endowed males that produce gametes in epigenetically good states, females can increase their fitness directly through increased fertilization success or indirectly through epigenetic effects on the fitness of offspring and potentially subsequent generations. Also watch the video abstract.
雌性对标志雄性基因质量的性状的选择，预计会侵蚀适合度的可遗传变异，从而削弱选择的益处。这种矛盾被称为“lek悖论”，它激发了广泛的群体遗传学理论，但仍未得到解决。邦杜里安斯基和戴最近的建模得出结论，当雄性状况由单代传递的环境诱导因素决定时，代价高昂的雌性偏好最能得以维持。在此，我们用明确的表观遗传学术语重新构建了他们的模型，并回顾了相关证据，即环境诱导的父本效应是通过精子中的表观遗传变化介导的。非编码RNA表达、DNA甲基化和组蛋白修饰对饮食、压力、毒物和随机事件高度敏感。表观遗传变异在每一代都会更新，不会因选择而耗尽。通过选择在表观遗传状态良好时产生配子的优质雄性，雌性可以通过提高受精成功率直接增加适合度，或者通过对后代以及可能的后续世代适合度的表观遗传效应间接增加适合度。另请观看视频摘要。
